activated receptor alpha (PPARα), a ligand-inducible nuclear transcription factor that has been implicated in the pathogenesis and treatment of tumor including lung cancer . However, the exact role that PPARα signaling plays involved in non small cell lung carcinoma (NSCLC) biology and the mechanisms by which PPARα ligands suppress tumor cell growth have not been Stattic cell line fully elucidated. A report showed that NAC could increase PPARα activity . Herein, our results show that NAC inhibits expression of PDK1 expression through PPARα-mediated induction of p53 and inhibition of p65 protein expression. Methods Culture and chemicals NSCLC cell lines H1650, A549, H1792, H2106, H460 and H358 were obtained from the American Type Culture Collection (Manassas, VA, USA), and were grown in RPMI-1640 medium supplemented with 10% FBS, HEPES buffer, 50 IU/mL penicillin/streptomycin, and 1 μg amphotericin. All
cell lines have been tested and authenticated for absence selleck inhibitor of Mycoplasma, genotypes, drug response, and morphology in the Laboratory in May 2010 and April 2012. Polyclonal antibodies specific for PDK1, PPARα, p65, p50 and p53 were purchased from Cell Signaling Inc (Beverly, MA, USA). The Dual-Luciferase Reporter Assay kit was obtained from Promega (Shanghai, China). N-Acetyl-Cysteine (NAC), GW6471, fenofibrate and all other chemicals were purchased from Sigma Chemicals, Inc. (St. Louis, old MO, USA) unless otherwise indicated. Treatment with PDK1, PPARα, p65 and p53 small interfering RNAs (siRNAs) The siRNA human PDPK1 (EHU071261) was ordered from Sigma, PPARα siRNA (sc-36307), and p65 siRNA (sc-29410) were purchased from Santa Cruz Biotechnology. Signal Silence p53 siRNA (#6231) was ordered from Cell signaling. The control nonspecific siRNA oligonucleotide (D-001206-13-05) was purchased from Dharmacon, Inc. (Lafayette, CO, USA). For the transfection procedure, cells were grown to 60% confluence, and PDK1, PPARα and p53 siRNAs and control siRNA
were transfected using the oligofectamine reagent (Invitrogen). Briefly, oligofectamine reagent was incubated with serum–free medium for 15 min. Subsequently, a mixture of respective siRNA was added. After incubation for 30 min at room temperature, the mixture was diluted with medium and added to each well. The final concentration of siRNAs in each well was 70–100 nM. After culturing for 30 h, cells were washed, resuspended in new culture media in the control or treated plates for an additional 24 or 48 h for the following experiments. Western blot analysis Equal amounts of protein from whole cell lysates were solubilized in 2 × SDS-sample buffer, separated on SDS-polyacrylamide gels. The separated proteins were transferred onto nitrocellulose using a this website Bio-Rad Trans Blot semidry transfer apparatus for 1 h at 25 voltages, blocked with Blotto with 5% nonfat dry milk and 0.1% Tween 20 for overnight at 4 C, and washed with wash buffer.